From: ken.edgett@asu.edu (Ken Edgett)
Subject: what really hppnd to Mars 96
Date: Wed, 18 Dec 1996 08:33:27 -0700 (MST)
Mars Educators-- I finnally got ahold of some text that clears up the confusion about what happened to Mars '96. The object that hit the earth Sunday evening, Nov. 17th was not the Mars craft itself... Ken Edgett Arizona Mars K-12 -------------------- UPDATE ON RUSSIAN SPACE PROBE USSPACECOM release 41-96 November 29, 1996 Peterson AFB, COLO.-- U.S. Space Command (USSPACECOM) has developed new information indicating that the Russian Mars '96 spacecraft likely came down on Nov. 16 instead of Nov. 17 as earlier reported. Any debris surviving the heat of this re-entry would have fallen over a 200-mile long portion of the Pacific Ocean, Chile, and Bolivia. We now believe that the object that re-entered on Nov. 17, which we first thought to be the Mars '96 probe, was in fact the fourth stage of the booster rocket. Confusion has surrounded key events and times in this mission, including the last stages of the rocket burn, the separation of the Mars '96 probe from the rocket, and the final re-entry into the Earth's atmosphere of the booster and the probe. USSPACECOM has now completed an extensive post-event analysis that has led to this new conclusion which supports Russian statements about when their Mars '96 probe re-entered the atmosphere. The area where any debris surviving this re-entry could have fallen is located along an approximately 50-mile wide and 200-mile long path, oriented southwest to northeast. This path is centered approximately 20 miles east of the Chilean city of Iquique and includes Chilean territory, the border area of Bolivia and the Pacific Ocean. The following is a chronological version of this space mission as observed by USSPACECOM: The Russians launched a SL-12 (Proton) four-stage rocket booster from the Tyuratam space launch facility at 3:49 p.m. EST on Nov. 16. Aboard the booster was a spacecraft known as the Mars '96 probe destined for the planet Mars. The USSPACECOM Space Surveillance Network (SSN) tracked the rocket and boosters throughout the first three stages of launch, and observed, recorded, and reported an object re-entering the Earth's atmosphere at 7:49 p.m. EST, Nov. 16. Absent an indication at the time of any problems with the Mars '96 probe, U.S. space observers ascribed the Nov. 16th event as the booster stage re-entry--which would be normal for a multistage rocket of this type. The planned separation of the fourth stage booster from the Mars '96 probe was not observed because it occurred out of view of U.S. space sensors. The USSPACECOM Space Surveillance Network did track a single object associated with this launch after monitoring the first three stages, which at the time was believed to be the booster's fourth stage still attached to the Mars probe. On Nov. 17 it became apparent that the Mars '96 mission had not achieved its intended trajectory to Mars. USSPACECOM continued to track in near-Earth orbit a single object thought then to be the probe attached to the fourth-stage booster. On that morning, the Russians requested, through NASA, USSPACECOM assistance in locating the Mars '96 probe. USSPACECOM impact predictions were forwarded to the Russians and Australians since initial predictions indicated that the re-entry would take place over Australia. Updated analysis of tracking data and orbital parameters placed the final impact of any surviving debris in the Pacific Ocean 150-200 miles off the coast of Chile at approximately 8:30 p.m. EST. On Monday, Nov. 18, the Russians announced that a failure on board their spacecraft prevented the probe from achieving its intended trajectory. The Russians also said their probe had likely re-entered the atmosphere on Nov. 16 between 7:30 and 8:30 p.m. EST. Based on this information, USSPACECOM analysts began a detailed review of all available data which ultimately led to our refined conclusions. USSPACECOM is not able to estimate what portion, if any, of the Mars '96 spacecraft might have survived re-entry. The United States' interest in providing this information is to clarify earlier preliminary U.S. reports that portions of the spacecraft re-entered over the Pacific Ocean hundreds of miles off the Chilean coast. We are now convinced that any impact of the probe that might have occurred on Nov. 16 would be within the area described which includes portions of Chilean and Bolivian territory. The Russians are in the best position to address the materials on board their spacecraft and whether any portion of the spacecraft might have survived the heat of re-entry. On Nov. 27, U.S. officials shared this information with the Russians and provided information to the governments of Chile and Bolivia concerning the Nov. 16 Mars '96 re-entry over portions of their territories. DIRECTORATE OF PUBLIC AFFAIRS, Headquarters, U.S. Space Command, 250 S. Peterson Blvd., Ste. 116, Peterson Air Force Base, CO 80914-3190 Phone: (719) 554-6889 FAX: (719) 554-3165 DSN: 692-6889 E-Mail: noussppa@spacecom.af.mil