This week marked a sombre period in the annals of NASA’s history. In a period of just 7 days – albeit spread across 50 years – America lost 17 astronauts in just three space flight related tragedies. Every year, the US space agency marks this loss of life – the results of the Apollo 1, Challenger and Columbia accidents – with a special Day of Remembrance on the 27th January. This year’s event was particularly poignant in that 2016 marks the 30th anniversary of the Challenger disaster.
It was on January 27th, 1967, that NASA suffered the first of these tragedies when, during a pre-launch rehearsal of what was intended to be the first manned flight of the Apollo Command and Service modules, a fire broke out inside the Command Module as the vehicle sat on the pad of Cape Kennedy Air Force Station Launch Complex 34. A combination of a pure oxygen atmosphere at a high internal PSI, and highly flammable materials used in the vehicle’s interior construction resulted in the deaths of Command Pilot Virgil I. “Gus” Grissom, Senior Pilot Edward H. White II, and Pilot Roger B. Chaffee in just 16 seconds.
Nineteen years later, on January 28th, 1986, NASA suffered its largest loss of life in a space mission up until that point in time. It occurred when Space Launch System mission 51L, the 25th flight in the space shuttle programme and the 10th flight of the shuttle orbiter vehicle Challenger – regarded as the veteran of the fleet, having flown more orbital missions than the other three orbiter vehicles at that time – exploded 73 seconds after launch, resulting in the loss of all seven crew.
Tragedy struck the space shuttle programme again on February 1st, 2003, when the space shuttle Columbia broke-up following re-entry into the Earth’s atmosphere at the end of mission STS-107, killing all seven crew. On board were Commander Rick Husband, Pilot William McCool, Payload Commander Michael Anderson, Mission Specialists Laurel Blair Salton Clark, Kalpana Chawla, David M. Brown, and Payload Specialist Ilan Ramon, a colonel in the Israeli Air Force and the first Israeli astronaut.
There have of course been other lives lost within the fraternity of astronauts and cosmonauts over the decades. However, these three tragedies perhaps stand larger than others because NASA has always undertaken its missions in the full glare of the public and media spotlight. Apollo 1, for example, was the headline mission for America meeting President Kennedy’s requirement for “landing a man on the Moon and returning him safely to the Earth” before the end of the decade. Similarly, STS-51L, the Challenger mission, had been specifically engineered to be in the public eye, featuring as it did the first teacher in space, Sharon Christa McAuliffe.
McAuliffe had been selected from more than 11,000 applicants to participate in NASA’s Teacher in Space Project, initiated by US Present Ronald Reagan and intended by NASA to rejuvenate public interest in the space programme, which has been declining steadily since the first space shuttle flight in 1981. The gamble paid off and McAuliffe, became a media sensation, attracting world-wide public interest in STS-51L; so much so that it has been estimated that around 17% of Americans watched Challenger’s lift-off live on television as a direct result of McAuliffe’s presence on the mission, and that around 85% heard about the disaster within an hour of it occurring (and if that doesn’t sound unusual, remember 1986 was well before the Internet and media revolution what has placed information and news at our fingertips wherever we are).
It could be argued – particularly with regards to Challenger, and also with Apollo 1, that the disaster could have been avoided. Warnings about the precise type of failure which caused the loss of Challenger date back as far as 1971, which tests carried out in 1977 revealing the risk of what because known as an O-ring failure being inherent in the design of the shuttle’s solid rocket boosters.
Things are less clear in the case of the Columbia tragedy; while it has been suggested that a rescue mission might have been mounted using the shuttle orbiter Atlantis, which was being prepared for a mission due to lift-off at the start of March, 2003. However, in order to get the vehicle flight ready for a launch ahead of the February 15th deadline (the point at which lithium hydroxide, a critical part of the systems used to remove carbon dioxide from the air in a space vehicle, would run out aboard Columbia), was itself fraught with risks.
But whether they could be avoided or not, these three disasters remind us that the cost of becoming a space faring civilisation – something which could be vital to our survival – is not without risk. Which is why I’ll close this part of Space Sunday with the words of Francis R. Scobee, the Commander of STS-51L, written shortly before his death aboard the Challenger:
Eyes on Mars
This year, Mars is once again in opposition – meaning it is on the opposite side of the Earth to the Sun, and is therefore passing along the point in its orbit when it is closest to the Earth. Such oppositions occur roughly once every 26 months, and mark the best time in which to launch a mission to Mars, as the flight time is only around 6-8 months, and the trajectory from Earth to Mars is the most energy-efficient.
But not all Mars oppositions are equal. The planet is in something of an elongated orbit around the Sun when compared to Earth, so the distance between the two worlds at their “closest approach” can vary. However, 2016 marks the start of 3 opposition periods where Earth and Mars are at their closest – something which only happens around every 15 to 17 years. This means that in May of this year, Mars will be a mere 75.3 million kilometres (46.5 million miles) from Earth, give or take a few thousands km.
It also means that Mars is going to appear in the spring sky brighter than it has done any time in the last 13 years. At its best, in late May, the planet will appear nearly twice as bright and more than 18 percent wider than at its previous good opposition in April 2014. This makes it an ideal candidate for viewing if you own a modest telescope – although those living above 40 degrees of latitude will have to look for Mars low on the horizon. Unfortunately, whenever Mars has an especially close opposition, it is in the southern part of the zodiac, and thus will never get higher than about 28 degrees (around 36 cm or 14 inches) above the southern horizon in the middle of the night.
Opposition this year also coincides with a number of other notable events in Mars’ calendar. In April, the planet will enter a period of retrograde motion when seen against the backdrop of stars. This will see the planet apparently come to a stop in its eastward progress across the sky before travelling “backwards” for some two months, and then resuming its march eastwards once more. This is the result of the Earth – being closer to the Sun and orbiting it somewhat faster than Mars, periodically “catching up” and “overtaking” the Red Planet as each moves in their respective orbits.
On October 29th, Mars reaches perihelion – the point in its orbit when it is closest to the Sun – which is a further reason for this year’s opposition offering us a particularly bright Mars to observe. This marks the opposition as being “favourable”, or perihelic. And if that is not enough, before this, on July 4, just over a month after Mars’ closest approach to Earth, the planet will be at one of its own equinoxes. So when Mars appears at its largest and brightest, skywatchers get to see nearly all of the Red Planet from pole to pole. As Mars’ southern hemisphere is coming out of winter, a prominent ice cap should be visible.
So, if you do have a decent telescope and can get a good view of Mars (particularly those of you in the southern hemisphere), check your star maps and keep an eye out through April to July! Or, if you can’t wait until then, you can catch Mars much higher in the sky from northern latitudes during February, where it can be seen with Mercury, Venus, Saturn and Jupiter, as the JPL February skywatching update below, reveals.
Flight over Ceres
As I’ve been reporting over the past few months, the joint NASA / ESA Dawn mission has been mapping Ceres, one of the solar system’s three “protoplanets” located in the asteroid belt between the orbits of Mars and Jupiter.
Dawn is the first mission to visit Ceres, and arrived there in March 2015, after a voyage which also saw the mission spend 14 months studying another of the asteroid belt’s protoplanets, Vesta, between 2011 and 2012. Currently, Dawn is in its final and lowest mapping orbit around Ceres, just 385 km (240 mi) above the surface.
On January 29th, NASA / ESA released a new computer animation of a simulated flight over Ceres, produced from images captured by Dawn’s camera system. The movie shows Ceres in enhanced colour, which helps to highlight subtle differences in the appearance of surface materials. Scientists believe areas with shades of blue contain younger, fresher material, including flows, pits and cracks. It emphasises the most prominent craters, such as Occator, and the tall, conical mountain Ahuna Mons.
The film has been produced by members of Dawn’s framing camera team at the German Aerospace Centre, DLR, using images from Dawn’s high-altitude mapping orbit, which occurred between August and October 2015, when the vehicle was some 1,450 km (950 mi) above the surface of Ceres.