NASA’s spacecraft recently conducted an elaborate dress rehearsal of an asteroid’s likely arrival to Earth by colliding with an innocent rock at 14,000 miles per hour – thrilling scientists at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland who ran this mission under contract from NASA.
Mission controllers at Laurel rejoiced and celebrated after witnessing Dimorphos’ image become ever larger and brighter in images being beamed back down to Earth.
NASA shuttles are designed to carry humans into space and back, so any significant mishap would have devastating repercussions. Unfortunately, NASA has experienced more than its share of catastrophes: In 2003, Columbia broke apart during reentry, killing its crew. Hubbard recalls how quickly the mood turned from excitement and anticipation to despair as astronauts likely died from rapid depressurization or collision damage with atmospheric layers as their bodies hit Earth’s atmosphere without protection.
Recent events saw NASA’s Mars Climate Orbiter spacecraft vanish into space due to a botched unit conversion at California’s Jet Propulsion Laboratory. The embarrassing error sent its $125 million spacecraft hurtling too close to Mars’ atmosphere, where it vaporized and broke apart into pieces live on television before eventually dissipating completely into dust clouds. A teacher from New Hampshire named Christa McAuliffe had planned on becoming the first educator ever in space if all went according to plan.
Why did it happen?
Mishap arose from an error in the spacecraft’s navigation system. Engineers from Lockheed Martin and JPL misinterpreted a set of numbers describing thruster firings as expressed in pounds, instead assuming they were expressed as newtons; this led to small inaccuracies which compounded over time.
Unknown to investigators is what caused the error; however, no power outages or malfunctions that would compromise its safety were experienced by the probe as a result of it. Therefore, the crash should have no lasting ramifications on future missions for NASA such as its long-term Mars expedition plans.
On January 28th 1986, seven astronauts died when the Challenger shuttle exploded during launch, due to foam that hit it during launch and caused a hole in its left wing, releasing gases and smoke that caused it to disintegrate on reentry causing catastrophic destruction of its crew and loss of lives. A Presidential commission known as Rogers Commission investigated what led up to this tragic event, ultimately concluding that foam hitting it caused it.
How did it happen?
Spacecraft that have gone down are yet another reminder of the perils associated with exploration.
The most notorious example was the 1986 Challenger disaster, when its parts came apart 73 seconds into flight and killed all seven crew members onboard.
Problems with navigational computers were partly responsible for this error: Engineers at Lockheed Martin’s Jet Propulsion Laboratory in Colorado used English units, not metric ones, for acceleration readings; their computers mistook this for newton-seconds2, leading to inaccurate results.
An investigation conducted by a commission appointed by then U.S. President William Rogers revealed several errors that contributed to the tragedy, such as an O-ring which lost its elasticity when exposed to near-freezing temperatures, as proved by famed physicist Richard Feynman by twisting it in a vice and submerging it in ice water – leading to misread readings that sent the spacecraft on an unexpected course and led directly to its catastrophic collision with Earth’s orbital path and led to tragedy.
What is the next step?
Space junk–defunct satellites and debris–doesn’t present much of a threat to space exploration right now; however, it can interfere with other satellites in orbit. Therefore, several countries like Russia conduct missile tests which destroy satellites orbiting in space creating even more debris; as well as performing hundreds of collision avoidance manoeuvres each year to minimize any interference between satellites in orbit.
Roscosmos, Russia’s space agency, lost contact with Luna-25 shortly before it was scheduled to land on the moon on Saturday morning – meaning this mission may never go forward and become the first lunar landing since 1976 when Russia was part of the Soviet Union.
DART successfully targeted Dimorphos, an asteroid moonlet orbiting larger Didymos. The mission’s one-way trip demonstrated we can intentionally collide spacecraft with an asteroid to alter its orbit; however, scientists must still observe Didymos to validate whether DART’s impact changed its path as intended.