tneff@bfmny0.UUCP (Tom Neff) (07/19/89)
In article <1699@infinet.UUCP> rhorn@infinet.UUCP (Rob Horn) writes: >In article <4304@eos.UUCP> eugene@eos.UUCP (Eugene Miya) writes: >> ... You will see the great unknowns at the time: >>Was the surface of the moon hard or miles of dust for a lander to sink? > >There were even two series of Lunar probes launched to specifically >answer this and related questions. It was nice back in the days when >you could have short turnaround simple missions. Specific focused >goals and specific focused schedules are so much easier to work with >than ongoing generic projects. Whoa. Assuming Zond doesn't count, there were two programs where unmanned spacecraft touched the lunar surface: Ranger and Surveyor. Ranger was a hard ballistic impact probe which relayed TV pictures on the way down. The final pictures were taken a few thousand feet above the surface; nobody really knew what happened when a Ranger hit. Dust or basalt would have extinguished the craft with equal efficiency. The first real answers about Lunar composition (remember to forget Zond) came from Surveyor. It did everything you could have asked -- it was a terrific program, my all time favorite until Viking. (After Viking, it's a tie.) But it was NOT a short turnaround mission. In fact it was one of the few vestiges of the PRE-Apollo, pre-Kennedy-challenge notion of the US space program. Surveyor had been on the books for about six years. With the crash Kennedy program, the three manned spacecraft became top priority and Ike's stuff languished at JPL, underfunded and behind schedule. In 1963 or 64 it was realized that Surveyor could provide key answers needed to build an LM. (I don't think anyone at NASA took Gold's theory of mile deep dust oceans very seriously, but it still makes a difference whether you're landing on bricks or sand.) So Surveyor got a funding and management push along with the Lunar Orbiter cameras (now THERE was a simple mission). For me, Surveyor was the real first glimpse of the Moon as another world. When Apollo astronauts followed in its footsteps (literally with 12), we saw an awesome sight -- one which had run in LIFE three years before. -- "My God, Thiokol, when do you \\ Tom Neff want me to launch -- next April?" \\ uunet!bfmny0!tneff
dsmith@hplabsb.HP.COM (David Smith) (07/20/89)
In article <14475@bfmny0.UUCP> tneff@bfmny0.UUCP (Tom Neff) writes: >>>Was the surface of the moon hard or miles of dust for a lander to sink? >> >>There were even two series of Lunar probes launched to specifically >>answer this and related questions. > >Whoa. >Assuming Zond doesn't count, there were two programs where unmanned >spacecraft touched the lunar surface: Ranger and Surveyor. Ranger was a >hard ballistic impact probe which relayed TV pictures on the way down. >The final pictures were taken a few thousand feet above the surface; >nobody really knew what happened when a Ranger hit. Dust or basalt >would have extinguished the craft with equal efficiency. Whoa right back. Ranger was indeed launched to answer this question. Rangers 3-5 had seismometers encased in balsa spheres, attached to retrorockets. These packages were supposed to separate from the main spacecraft, brake to a stop 1100 feet altitude, jettison the retros, then fall from there. After rolling to a stop, they were to transmit readings back. If the balls sank into dust, the signals would reflect that. Rangers 1 and 2 were engineering spacecraft, not intended to hit the moon. Their Agena stages (2nd stage on top of Atlas) failed to fire to get out of parking orbit. Ranger 3 was launched 30,000 miles off course by the Agena, and was only able to to cut the error to 23,000 miles with its course-correction motor. As it passed the moon, it failed to aim its high-gain antenna at the Earth, so its photos weren't received. Ranger 4's sequencer failed. Ranger 5's power failed shortly after trans-lunar injection. After this, the spacecraft were simplified to be camera-only probes, and then Ranger 6 failed to turn on its cameras. Talk about snake-bitten. But at any rate, three Rangers had attempted to get an instrument to survive a moon landing. -- David R. Smith, HP Labs dsmith@hplabs.hp.com (415) 857-7898
tneff@bfmny0.UUCP (Tom Neff) (07/21/89)
>Whoa right back. Ranger was indeed launched to answer this question. >Rangers 3-5 had seismometers encased in balsa spheres, attached to >retrorockets. These packages were supposed to separate from the main >spacecraft, brake to a stop 1100 feet altitude, jettison the retros, >then fall from there. After rolling to a stop, they were to transmit >readings back. If the balls sank into dust, the signals would reflect >that. Damn. David's completely correct and I am a complete fool to have forgotten the balsa breakaways. I remember being fascinated by the idea of WOOD on the moon at the time! My public apologies. Phone Tree Alert - Full Funding for Ranger Mark II! -- 10 news postings = 18 Neff-Minutes | John Q. American at Deere School (NM's). -- The Pentagon | jqa@complete.FOOL.NET -- "My God, Thiokol, when do you \\ Tom Neff want me to launch -- next April?" \\ uunet!bfmny0!tneff
gvg@hpcvlx.HP.COM (Greg Goebel) (07/24/89)
> > Damn. David's completely correct and I am a complete fool to have > forgotten the balsa breakaways. I remember being fascinated by the > idea of WOOD on the moon at the time! > > Tom Neff > I read an article on Pegasus in MECHANICAL ENGINEERING and found out to my surprise that the wings were overlaid with a layer of cork -- it burns off at high velocity. +---------------------------------------------------------------------+ | Greg Goebel | | Hewlett-Packard CWO / 1000 NE Circle Boulevard / Corvallis OR 97330 | | (503) 750-3969 | | INTERNET: cwo_online@hp-pcd | | HP DESK: CWO ONLINE / HP3900 / 20 | +---------------------------------------------------------------------+
neal@lynx.uucp (Neal Woodall) (08/29/89)
In article <14475@bfmny0.UUCP> tneff@bfmny0.UUCP (Tom Neff) writes: >The first real answers about Lunar composition (remember to forget Zond) >came from Surveyor. It did everything you could have asked -- it was a >terrific program, my all time favorite until Viking. How interesting....I too have always had a "soft spot" in my heart for the Surveyor craft. They were really neat little probes, and looked very much like what one would imagine a "space probe" (as opposed to a plain-old earth-orbiting satellite) looked like. BTW, what ever became of the pieces of a Surveyor that wer brought back by some of the Apollo astronauts....one of the Apolllo landings just happened to be about 300 meters from one of the Surveyors. It might be interesting to have everyone post to the net which of the unmanned probe missions is their favorite.....it could provide some interesting discussions! Pioneer, Voyager, Viking, Surveyor, Mariner....which is your personal favorite? Neal