The Chief Technologist’s view of the HGS-1 mission
by Jerry Salvatore
|I encountered Ron Swanson, president of Hughes Global Services (HGS), in a local parking lot in early January and he suggested, “what about the Moon?”|
In my efforts to verify my conclusion with a detailed computer simulation, I met Cesar Ocampo, a junior engineer who had the expertise to run commercial off-the-shelf orbital analysis software developed by Analytical Graphics, Inc (AGI). When he confirmed my estimated delta velocity numbers in detail, my efforts focused on how to accomplish the complex maneuvers, attitude stabilization, and orbit and attitude determinations during the entire sequence of maneuvers that would be required.
Swanson and Skidmore worked with Steve Dorfman, Hughes’ Vice Chairman, to secure salvage rights from the insurance underwriters and enable mission planning and execution to proceed as quickly as possible because of adverse changes in the AsiaSat 3 orbit. Dorfman was ultimately responsible for giving the “go” to proceed with the mission, as well as suggesting we execute a second flyby to improve the final HGS-1 geosynchronous orbit.
No one at Hughes was authorized to discuss the mission with any external individual or company. What apparently happened were grassroots conversations between Hughes engineers, who were not authorized to conduct those conversations, and Innovative Orbit Design (IOD)/Microcosm personnel (Ridenoure and Ed Belbruno) who were trying to push an approach that could not work. I was not aware of any conversations between Hughes engineers and Ridenaure/Belbruno until late February 1998, after I conceived the approach that was actually flown. When Ocampo told me he was talking to Belbruno, I told him that Belbruno’s “Weak Stability Boundary” (WSB) approach, which required the spacecraft to transit multiple lunar radial distances from the Earth, was untenable because there was no telemetry, tracking, and command (TT&C) capability at these ranges. I advised Cesar not to talk to him again; specifically, not to reveal how we were going to make it happen. (Hughes had previously reminded all involved of their obligation to protect Hughes’ proprietary information). Against policy and my admissions, Ocampo disclosed Hughes’ proprietary information on March 27, telling Belbruno our strategy of a free return trajectory around the Moon.
I started to enlist some dozen volunteers to execute the developing plan. One of my principal concerns was how to determine where HGS-1 was at any time during this landmark lunar mission. Based on my recommendation, HGS hired a world-known orbit determination expert, Tom Martin, who could use range, azimuth, elevation, radar, Doppler data, and telescopic HGS-1/star observations to define any current spacecraft orbit. Lacking adequate support or experience from the Space and Communications Group (SCG) orbital operations department, HGS (on my recommendation) retained two former Hughes employees, exceptional women that had supported SCG during the Westar 4/Palapa B2 recovery in 1984 and the Intelsat 6/F3 reboost mission in 1992. They would define the parameters of all required maneuvers as well as define current orbit and attitude status. Caroline Shallon came in from Israel and Mery Pinhiero came in from Brazil to assist in making this mission possible.
AGI, an up and coming company with a versatile software product, Satellite Tool Kit (STK), became so enthralled with this mission that they offered free animated video updates of the orbit and real-time animations of spacecraft maneuvers. Discussions between HGS and Paul Graziani, CEO of AGI, allowed them full access to all operational activities on a no fee basis in return for their visual reports. Eventually, after public announcement of the mission start, they published the real time orbit of HGS-1 on their website.
Attitude stability and control was a significant problem during this mission because of mass property variations during the many required burns. Fred Linkchorst, Laura Fields, and Elias Polendo unselfishly stepped in to assist SCG in this most important endeavor. Other individuals like Jeff Robinson (Thermal), James Shirvanian and Jackie Hoang (Propulsion), Bill Brooks and Steve Enright (Flight controllers), Phil Cohen and Dave Norman (Syscom), and Joe Lagana, (deceased, Mass properties) were key contributors to the success of the mission. Many other wonderful and talented people at Hughes would pitch in along the way.
After HGS secured salvage rights to AsiaSat 3, the spacecraft was renamed HGS-1 and the first burn to raise its orbit for the first lunar flyby was initiated on April 10, 1998. The complex sequence of13 burns were executed from ground stations in Fillmore, California, and Jakarta, Indonesia, in anticipation of a May 13 flyby. The astronomy community in Europe realized in late April that AsiaSat 3 was “rising from the ashes” and, as Ridenoure correctly reports, triggered a public news conference by HGS on April 29. With this public announcement and the silence of SCG during April, Belbruno and Ridenoure were dismayed about why they were not party to what was really going on. This was somewhat understandable, since they still believed it was their idea to use the Moon even if their approach was impossible to execute.
Once IOD learned the HGS-1 saga was underway, they changed their tactics to publically imply that they gave SCG, specifically myself, the inspiration for using the moon for the recovery. They initiated a public relations campaign, as discussed in Ridenoure’s article, to get a local newspaper, the Daily Breeze, to acknowledge their alleged contribution to the flyby.
I honored my management’s directive not to divulge any information to the public until the mission was completed. I refused to give answers to many questions from reporters I knew at Aviation Week and Space Technology (AW&ST). Unfortunately, the Belbruno/Ridenoure public relations campaign continued, despite their ignorance as to what was actually taking place. Belbruno and Ridenoure contributed nothing to the HGS-1 rescue.
|When I solicited Ocampo’s expertise in mid-January 1998 to verify my calculations about the lunar flyby approach I developed, I had no idea of who Ed Belbruno was or what any “WSB” solution was.|
Prior to the start of operations, I wrote a patent application, titled “Free Return Lunar Flyby Transfer Method for Geosynchronous Satellites,” that was filed on April 9, 1998 and approved as US patent number 6,116,545 on September 12, 2000. After the first lunar flyby when we decided to go around one more time (at Dorfman’s suggestion), I wrote a second patent application, “Free Return Lunar Flyby Transfer Method For Geosynchronous Satellites Having Multiple Perilune Stages,” that was filed on May 15, 1998, and approved as US patent number 6,149,103 on November, 21, 2000.
Ridenoure makes no mention of litigation, except in a footnote, where he jests it “would be like wanting to see how sausage is made, wouldn’t it?” He is trying to dismiss an extremely relevant point. After HGS-1 had successfully achieved a geosynchronous orbit south of Hawaii, the Belbruno/Ridenoure public relations campaign adopted a new tactic, namely, IOD sued Hughes for infringing on IOD methodologies. Apparently, IOD claimed that the two patent applications submitted by Salvatore were “subsets” of that now famous WSB theory. After many months of discovery and depositions, along with significant legal fees, the case was dismissed by summary judgment—it did not even proceed to trial. The court found in Hughes favor and ordered IOD to pay Hughes for a portion of Hughes expenses. In reference to Ridenoure’s footnote, nobody needed to watch sausage being made; rather, everyone had to accept the fact that a “square peg doesn’t fill a round hole.”
During the mission, Ocampo was a junior member of the staff and not privy to activities taking place at higher levels within SCG and HGS. He did not have a technical or business decision-making role. His comments are from his limited perspective as a trajectory analyst only. It is unfortunate that Ocampo maintained some dialogue with IOD, contrary to Hughes’ specific instructions. Ocampo was deposed by IOD’s attorneys. He had ample opportunity, under oath, to answer any of their questions and offer his opinions. If he had said anything supporting IOD’s case, it would have been exploited.
Ridenoure also fails to cite the definitive paper on the HGS-1 mission delivered at the 50th International Astronautical Congress (IAC) in Amsterdam, the Netherlands, in October 1999. I wrote this paper, “Mission Design and Orbit Operations for the First Lunar Flyby Rescue Mission” (IAF-99-A.2.01), and presented the paper at the conference. This paper discusses all technical and operational aspects of this five-month mission.
Ridenoure cites a paper written by Ocampo some six years later (2005) titled, “Trajectory Analysis of The Lunar Flyby rescue of AsisSat 3/HGS 1,” and says we are all indebted to Cesar Ocampo for thoroughly documenting much of what happened technically and programmatically inside Hughes during this time” and “see page 234 for Ocampo’s frank summary of what was going on behind the scenes.” It would have been impossible for Ocampo to know what was truly occurring at the decision-making level, as he was a junior analyst not privy to such information. Ocampo never sent me this paper nor asked me for comments or permission on its contents.
In summary, let’s examine the facts:
Belbruno and Ridenoure knew that the Moon was the key to any possible salvage attempt. They had no viable solution and were incapable of marrying HGS-1 operations to any kind of lunar “handshake.” They pursued backdoor conversations with Ridenoure’s cited SCG insider personnel to make sure they would be at the “party” if and when a viable solution was proposed and executed. They were setting up to litigate, which they eventually—and unsuccessfully—did.
|Steeped in their exclusive “Fuzzy Boundary” theory, they could not possibly imagine somebody else using the Moon in an elegantly straightforward way to slingshot the errant satellite back to the Earth like Apollo 13.|
Ocampo published his paper six years after my IAC paper. In the concluding remarks of this paper, Ocampo states, “It is hoped that this article has served two purposes. The first is an official acknowledgment by the author of the contribution of Edward Belbruno and Rex Ridenoure. The second is the presentation of a complete technical description of the rescue operation.” The first purpose was never achieved because he could not define their contribution. The second purpose was achieved because he took my complete technical description of the rescue operation from the IAC paper, without my permission, and got it exclusively under his name.
Many of Ridenoure’s comments in the “Beyond GEO” article have been discussed and dissected above in the previous section of this essay. However, there are two key paragraphs toward the end of the article that support my opinion above. Ridenoure writes, “Thanks to the efforts of our front-line champions inside Hughes, our many supporters in the space community, and the connectivity of the Internet, the story about how the core, enabling idea of using the Moon to salvage AsiaSat 3 entered into the option trade space at Hughes was not buried by the personal or corporate motivations that apparently wanted to squelch the facts. The story got out and stuck.”
Here it is: their contribution was “the core, enabling idea of using the Moon to salvage AsiaSat 3.” Steeped in their exclusive “Fuzzy Boundary” theory, they could not possibly imagine somebody else using the Moon in an elegantly straightforward way to slingshot the errant satellite back to the Earth like Apollo 13. Moreover, how could this idea be possibly triggered by a conversation in a parking lot?
The second key paragraph by Ridenoure states, “For the annual Aviation Week & Space Technology magazine Laureate Awards, arguably the closest thing aerospace has to the film industry’s Academy Awards, Salvatore, Ocampo, Belbruno, and Ridenoure were nominated for the 1998 Best Achievement in Space award.” Ridenoure’s last statement in the previous paragraph—“The story got out and stuck”—was clairvoyant. Ridenoure and Belbruno got one of the highest national awards for “the core, enabling idea for using the Moon to salvage AsiaSat 3,” even though my concept was triggered by memory of the Apollo 13 rescue mission in 1970. Using the Moon as an essential element of a geosynchronous transfer orbit had never been proposed before. However, I introduced (in the public domain) the idea of the “super-synchronous transfer orbit” in planning the Intelsat 6 STS reboost mission in 1992. This increased the life of the salvaged satellite by about two years. This technique became common in the industry and is still in use today, some 20 years later.
Apollo 13 was a damaged spacecraft with limited propulsion heading for the Moon. The genius of this rescue was to combine limited propulsive burns of the lunar module with a lunar slingshot back to Earth that set up a proper reentry angle and speed for a safe ballistic return of the astronauts to Earth.
AsiaSat 3 was a healthy spacecraft with full propulsion but an impossible task to reach GEO from its highly inclined orbit relative to the Equator. The genius of this rescue was to use part of the propulsive capability to go to the Moon, use the Moon’s slingshot to raise its perigee to synchronous altitude, remove as much inclination as possible on a lunar flyby near the Equator, and then brake “like hell” with the remaining propulsion on the return to perigee. The braking maneuver would lower the apogee from roughly twice lunar distance to synchronous radius, resulting in a geosynchronous (24 hour) orbit. The second lunar flyby was ad hoc and performed to maintain the perigee at synchronous radius but further reduce the inclination of the eventual orbit. The double lunar flyby reduced the inclination of HGS 1 from 51.6 degrees to about 8 degrees and achieved a geosynchronous orbit south of Hawaii.
I received my first AW&ST laureate award in 1984 at the age of 41. I worked for 11 months with NASA to return two stranded satellites, Westar 6 and Palapa B2, to earth with the shuttle (STS-51A). I had the opportunity to fly them both, refurbished, back up to the geostationary corridor in 1990. I would not be able to execute that mission again at the age of 55, when the HGS-1 double lunar flyby was accomplished.
|The genius of this rescue was to use part of the propulsive capability to go to the Moon, use the Moon’s slingshot to raise its perigee to synchronous altitude, remove as much inclination as possible on a lunar flyby near the Equator, and then brake “like hell” with the remaining propulsion on the return to perigee.|
The HGS-1 mission, the first and maybe the last of its kind, lasted some five months, and required less youthful stamina but the more thoughtful experience of an older pilot. I was honored to receive my second AW&ST award but was disturbed by my company in the award. How could this most prestigious space magazine reward two pretenders whose only claim was the Moon was necessary for the salvage? They capitalized on a propaganda campaign to steal this award. Unfortunately, I was duty bound not to speak openly to the media. With my silence, the media made a serious mistake. Ridenoure was right 15 years ago: “The story got out and stuck.” He is dead wrong to resurrect this fictional story on the 15th anniversary of this historic event. The real story is now in the public domain!
Ocampo quotes: “the lack of ethics and integrity of certain HSC officials concerning the acknowledgement of external contribution from Belbruno and Ridenoure placed a blemish on the mission”. I ask the reader, after reading the facts and my opinions in this article, where the lack of ethics and integrity are, and who blemished whom and continues to lie about this mission. If you come to the obvious answer, then I have written what I needed to say.
Thank you for reading and God bless the Hughes culture of excellence that allowed this mission to take place and become part of the Hughes SCG Heritage.