Dennis Wingo: Apollo vs Constellation
- Computers of Apollo program
- Draper lab
- No one had ever built such a small, compact computer
- Very first integrated circuit was in the 1963 Minuteman missile guidance but already designing Apollo computer by 1964. So they ICs basically not an option. Use point-to-point design of circuits.
- The rocket/space programs of 50s and 60s established all the basic techniques for computer design.
- Navigation was the key task
- Basic units derived from mainframes - Arithmetic Logic Unit (ALU)
- LM ALU had 15 bits plus 1 binary bit. Effective clock rate was 500kHz (vs 3GHz today)
- Memory access today takes around 1ns. For Apollo the core memory (ferrite beads) access time was 11.5 microseconds
- LM abort to orbit task - Buzz had developed the underlying design as a grad student. Had to process radar data hitting ground to get altitude.
- 23 microsecs to do an add.
- Draper developed first real-time OS in 36K of ROM and run in 16K RAM.
- Each subroutine outlined on one page of a flowchart. Could verify by hand each program.
- Didn't have registers. So increment/decrement operation had to be done via memory access.
- Hard timer meant a task had to finish at a fixed moment.
- Radar data processing during Apollo 11 landing failed but with core memory they could reset back to an earlier state and continue from there.
- Fairchild designers involved and they later went on to form Intel. So all microprocessors trace their heritage back to Apollo computer.
Questions:
- Current computer radiation tolerance
DOD requires radiation hardened computers. Alternative is simple shielding like tantalum. Also error correction codes. Even current memory has gotten to such small cell size that error correction built in.
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- Caught the last part of Loretta Hildago Whitesides discussion of Yuri's Night.
- Organizers of various parties were discussing strategies of dealing with NASA/company management
- Pary organizers were given Dancing Snoopy awards.
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Mark J. Sundahl - Space Tourism and The Space Treaties: Liability, Resuce & Finance
- He has been working on this area for a long time but only became serious issues after first space tourist began to fly.
- Besides problems caused by the space treaties, how might space tourist treaties benefit from them.
- Lists the various space related treaties - Outer Space Treaty (1967), Rescue Agremenet (1968), Liability Convention (1972), The Registration Convention (1975), The Moon Agreement (1979) - not signed by major space power.
- A space object is something launched, or attmpted to be launched, into outer space.
- An aircraft "derive(s) support in the atmosphere from the reactions of the air"
- Duties are applied to countries, not companies. The country then applies requirements on the companies.
- "When a space object is luanched into earth orbit or beyone, the launching State shall register the space object..."
- Suborbital vehicles don't need to be registered.
- When it comes time for industries in space, it may be time for new treaties.
- Liability for damage to or by a spacecraft.
-- "The launching state is absolutely liable to pay compensation for damage caused by its space object on the surface of the earth or to aircraft in flight."
- Money for damage is turned over to the state. Whether the state passes the money along to the private individual or entity tha suffered the damage is dealt with via that state's law.
- Liability for damage in space: "damage cuased elsewhere than on the surface of the earth to a space object of one launching State ... by a space object of another launching State the latter shall be liable only if the damage is due to its fault"
- Foreign national on a domestic suborbital spaceflight not liable to the foreign state under that treaty.