Brian J O'Brien AO

EASEP AND ALSEPs

Scientific activities on the Moon by Apollo astronauts were largely focussed on geological samples, photos and related investigations during their Extravehicular Activities (EVAs).  In addition, in 1965 NASA had selected 7 experiments from 90 proposals to be included in the Apollo Lunar Surface Experiment Package (ALSEP) to be deployed as a self-powered transmittng geophysical observatory at each Apollo landing site for years after each astronaut team had departed. My Charged Particle Lunar Environment Experiment (CPLEE)  was chosen as 1 of the original 7. Its purpose was to put compatible experiments on the Moon to search for relations with my rocket and satellite experimental measurements of electrons and protons causing auroras. Basically, CPLEE searched for (and found) aurora radiation when the extended geomagnetic tail generated by the supersonic solar wind flapped across the Moon particularly at times around full Moon. Only Apollo 14 deployed a CPLEE, after the Apollo 13 ALSEP was lost. The loss destroyed one major aim, of putting two CPLEEs at widely separated sites to distinguish between variations caused by time from those caused by space distance.

The original 7 PIs first met collectively with the first two aerospace bidders to build the ALSEP platforms on 11 and 12 January 1966. The 3 PIs with radiation experiments were instructed to add a "dust cover" over any apertures to block any dust which hypothetically might be disturbed by hypersonic  rocket exhausts from each Lunar Module (LM) carrying the astronauts from the Moon. The dust covers were to roll back or otherwise be removed long after the astronauts had been launched from the Moon. I supported the concept but asked what dust detector would measure the reality of any hypothetical dust. NASA Manned Spacecraft Center (MSC) instructed that no dust experiment would be deployed. Two major reasons given were that

·         no suitable dust experiment existed with an acceptable weight (less than 2 or 3kg) and

·         no very precious astronaut time, at nominal  US$1million per minute) could be spared for such a minor, non-selected experiment.

In colourful language I expressed my strong opinion that if I had to increase risks for CPLEE by adding  a complex retractable Dust cover including explosives on the Moon to roll it back, then a dust detector was essential, besides, a dust detector seemed simple commonsense in the face of uncertainties. That evening on the flight home from LA to Houston I invented a very small, simple dust detector experiment which would not require any astronaut time, and which turned out to weigh 270grams, built  of space-proven hardware with basic, very simple electronics. I submitted my proposal to NASA (NASA SC Control 44-006-054) for a DDE to become Number 8 experiment, be deployed on every Apollo and have its measurements be made available immediately to every PI with his own measurements. There are now 4 DDEs on the Moon at Apollo 11, 12, 14 and 15 sites. Some 30million digital measurements are in several archives -  including Goddard Space Flight Center (GSFC) - of movements of dust on the Moon, which Apollo astronauts found to be the Number 1 environmental problem on the Moon. We have peer-reviewed publications of 14 discoveries to date of the only such measurements published to date, other than NASA SP-214, NASA Apollo 11 Preliminary Science Report.  We showed in August 1969 the errors of SP-214 to the authors, and without our permission, our name was included as co-author. Our correct measurements and the opposite conclusion was published in October 1970 with MSC original authors and my name as lead author.

About four months before the launch of Apollo 11, three of the original large experiments  were stripped from the first ALSEP, which payload was postponed and flown by Apollo 12. The stripped-down package became EASEP (Early Apollo Surface Experiments Package), to be released from one hand of Buzz Aldrin in about 10 minutes. The two active, powered and transmitting experiments were the 47kg Passive Seismometer Experiment (PSE), and the 0.27kg  Dust Detector Experiment (DDE). Rocket exhausts of the first launch of men from the Moon caused polluting dust to be thrown on the shiny gold surfaces of the PSE, which greatly overheated by over 50 degrees F above its maximum top planned temperature. It failed after 21 Earth days, before its second lunar noon. But EASEP did survive its first freezing night of 350 hours and started operations again on the second morning until failing and being switched off before noon. It failed after 21 Earth days. .

and started operations again on the second morning until failing and being switched off before noon. It failed after 21 Earth days. The Apollo Lunar Surface Experiments Packages (ALSEPs) deployed by Apollo astronauts to be long-term geophysical observatories after astronauts returned to Earth were all mainly digital telemetry. Consequently for our telemetry analyses of two ALSEP experiments of CPLEE (a radiation experiment selected in 1965 by NASA as 1 of the original 7 prime experiments) and Apollo Dust Detector Experiments (DDEs) which I invented in 1966 as a hitch-hiking 8th  experiment, we made ourselves well equipped at Rice University to process digital telemetry and read 7-channel telemetry tapes. When I became visiting scientist at the University of Sydney in 1969 the School of Physics was already well equipped with SILLIAC, a pioneering computer.  We quickly added programs to process both CPLEE and DDE computer tapes of data , after Manned Spacecraft Center Computing group sent us test tapes before flight, to ensure compatibility.

However, the Space Physics Group at MSC was not well equipped with The University of Sydney proposal on June 10, 1969 submitted a zero-cost proposal to NASA Manned Spacecraft Center for zero-cost shared analyses of Apollo 11 tapes which made two predictions by O'Brien which occurred. First, EASEP would be significantly contaminated by dust. Second, NASA Manned Spacecraft Center (MSC) and personnel were not equipped to analyse the Apollo 11 digital data. MSC relied only on (noisy) analogue flight data from Bendix Aerospace Corporation, builder of EASEP, in flight  monitoring. They made do with paper charts from galvanometer readings from the Bendix  real-time flight-monitoring. Indeed they were not in the science room at Mission Control, but had charts or copies of charts passed to them (Jim Bates, pers.comm.). They were unable or unwilling to read significant effects in analogue traces through noisy telemetry through varying plasma clouds from rocket ascent. Further, in the group excitement during the operations of the lunar surface package on the second lunar day that the package was awake and functioning, those measurements from the Dust Detector Experiment in August were accidentally mistaken for being those from  the actual July Apollo 11 LM ascent.

Consequently, the Apollo 11 Preliminary Science Report (NASA SP-214) in 1969 contains a misleading report by the MSC authors that there was "no appreciable cell degradation caused by dust or debris from the Lunar Module ascent."  Figures 10-3 and 10-4 from that report plotted measurements made a month after LM ascent. Not only were the 142 Principal Investigators of lunar rock samples from the first and historic direct samples from the Moon misled, but the very strategies and importance of dust mitigation and management were grossly distorted for the entire Apollo missions and decades after. While we corrected this Apollo 11 mistake in part by having the MSC authors be co-authors to my subsequent published correct assessment using digital data from University of Sydney's SILLIAC, that publication did not occur until October 1970 by which time Apollo 12 and 13 missions had been completed.  The incorrect but historically important Apollo 11 report remained dominant in collective memories. The strategic damage to rigorous mitigation of movements of lunar dust was irretrievable under the inexorable schedules of landings. Dust remained the most significant environmental difficulty on the surface of Moon for Apollo astronauts and many experiments.

The Manned Spacecraft Center (now Johnson Spacecraft Center) gained a wide reputation -including at NASA Headquarters - of being anti-science during Apollo. High-level resignations after Apollo 11 gave evidence of this. We make no comment on recent histories.