NASA is talking the first step leading to development of a space rescue system.
The space agency is expected to issue a request for proposals to industry in the next few months for a study defining potential emergency conditions of a manned vehicle in space and how a system using existing or future space hardware could be used to meet them.
The space rescue development program will be headed by Edward H. Olling of the space station study office under the Manned spacecraft Center's Advanced Spacecraft and Technology Div.
It is not believed that the space agency, at this point, has the funds required to develop a space rescue system. But if industry could come up with a feasible system using existing launch vehicles and spacecraft from the Gemini and Apollo programs, the cost of the system could probably be lowered to the point where the funds might be obtained by reprogramming funds approved fro other projects.
A NASA official said last week that the RFP was ready to be issued to industry, but it was apparently later withdrawn because top officials refused to give their approval. Maxime Faget, MSC assistant director for engineering and development, said that MSC is currently wrestling with the work statement and plans to resubmit it to NASA Headquarters at a later date, but declines to say exactly when.
In addition to cutting the cost, the use of existing hardware would sharply reduce the time needed to develop the system. Thus, if the study proved such a system feasible, NASA could skip its usual phased procurement procedures and move directly to development.
Gemini 8 scare
Space rescue, although studied in-house at MSC among the functions of a logistic vehicle supporting a manned orbiting space station, was pulled out for separate study only recently when it apparently became obvious to NASA officials that Gemini 8 astronauts came very close to being stranded in orbit or to facing a very risky ballistic re-entry.
NASA has been under pressure by at least one member of Congress and some U.S. newspapers to develop a space rescue system. Rep. Olin Teague (D-Tex), according to press reports, demanded action after the successful March 16 recovery of Gemini 8 astronauts Neil A. Armstrong and David R. Scott after an almost-catastrophic failure in space.
The Gemini 8 spacecraft began to tumble out of control because of a stuck thruster shortly after the first successful link-up with an Agena target vehicle in space, forcing the crew to undock and to use the re-entry control system (RCS) to dampen an excessive roll rate of 360 per second.
Depletion of RCS propellant in orbit would have denied the crew attitude control during re-entry. RCS thrusters are used to hold the spacecraft in proper attitude during contact time of retro-fire, and to keep the blunt end forward to allow the heat shield to bear the brunt of re-entry heating. Without attitude control, the spacecraft could become aerodynamically unstable during re-entry, inducing a tumble that could endanger the crew and spacecraft to high-g structural loading and the risk of burning up.
Under terms of the study, the contractor will be called upon to classify emergencies from the standpoint of time necessary to effect a rescue. An MSC source told MISSILES and ROCKETS that a space rescue system, in order to cover all possible emergencies that may arise in Gemini and Apollo missions, would have to be designed for the "worst case."
Possible launch vehicles
This would demand a delta-V capability that could steer out of large out-of-plane (60 deg maximum) and out-of-phase (360 deg maximum) differences, as well as brute force propulsion that could match orbital eccentricities and orbital axes to accomplish a rendezvous in the minimum amount of time. Such a capability, he said, is far beyond the Gemini-Titan II combination, but begins to look "feasible" with a modified Gemini mounted atop a Saturn V.
A make-shift system using the Saturn IB or the Titan III launch vehicles might be used to cover most emergency situations in Earth orbit.
Space rescue systems are not feasible because most of the things required of them — rendezvous, docking and walking in space — have all been proved to be fairly easy space maneuvers.
While there is no launch vehicle in existence that can generate the required high delta V to cover all emergency situations, this could be compensated for by launching at a time when the rendezvous can be achieved quickly.
One of the systems proposed calls for adding a seat to the Gemini spacecraft so that it could be launched with only one man at the controls on rescue missions involving two astronauts.
Another calls for launching an unmanned spacecraft — carrying additional oxygen, water, food and power supplies — so that stranded astronauts could stay in space until a manned rescue vehicle arrives.
A third proposal calls for adding a seat to the Apollo spacecraft so that it could be used in rescuing three-man astronaut teams.