An unmanned rocket exploded. So what?

An unmanned rocket exploded. So what?
Not Diwali. Credit: Joel Kowsky/NASA, CC BY-NC

Sputnik was launched more than 50 years ago. Since then we have seen missions launched to Mercury, Mars and to all the planets within the solar system. We have sent a dozen men to the moon and many more to the International Space Station, along with a significant complement of female astronauts. Our communications, banking, television, security and transport sectors rely on satellites orbiting the Earth.

We have moved from a space race between nations to becoming a race that relies on space for many of its everyday activities. Perhaps this is why the explosion on take-off of the unmanned Antares has received such wide publicity.

The rocket was not carrying anything irreplaceable: it was a scheduled cargo mission, taking supplies to the International Space Station (ISS). Indeed, a Russian vehicle was launched soon after with a similar cargo, so the astronauts will not be in danger of going hungry. But, as with any accident, results from the explosion will have ramifications beyond the immediate issue of re-supplying the ISS.

So why is this launch failure so significant? One reason may be that the rocket was owned by a private company, Orbital Sciences Corporation. They are one of the two companies (the other being SpaceX) contracted by NASA to resupply the ISS following the end of the space-shuttle programme.

Orbital Sciences Corporation have a proud record of successful satellite launches, but this was only their second rocket to the ISS and third launch of their Antares medium-class launch vehicle. It is probably unfortunate that the company website states that Antares is designed to have a 95% (or greater) launch reliability.

Even if the accident investigation rapidly identifies the reason for the explosion, the time it will take to re-build the launch pad and ensure that the fault is fixed will delay Orbital Science's space ambitions. The price of shares in the company dropped by about 15% after the launch failure.

All private companies launching rockets into space will be affected. It is somewhat ironic that, although there have been enormous advances in space technology in terms of the instrumentation and equipment that is launched into space, the computer systems that control them and the basic mechanism of getting into space have not advanced much. Launch still relies on a controlled explosion, either from a liquid or a solid propellant. In other words, we are still mounting delicate things on top of a bomb.

Does this give confidence, as we become ever more dependent on orbiting satellites, and the promise of space tourism moves closer to reality? While there has been progress on most aspects of space flight, it seems that the very first stage, getting there, is likely to be the most hazardous. The Challenger disaster of 1986, when the space shuttle broke up during its launch, killing all seven of the astronauts, is a constant reminder of the dangers of space transport.

Up until the end of 2013, a total of 6,584 spacecraft had been launched, with 549 failures, a success rate of about 92%. The current generation of launchers are becoming increasingly reliable: success rates of 98.7% for the US Delta II vehicle, 97.1% for the Russian Soyuz launcher, and 94.6% for Europe's Ariane 5.

We are now in the position where airline transport was a century ago: warily regarding something that is generally safe, but which achieves notoriety when it goes wrong. In 2013, there were 29 fatal air accidents, the lowest figure in post-war history. This corresponds to less than one incident per million aircraft take-offs. We rarely consider the chances of an aircraft accident – maybe when we are instructed to pay attention to the safety demonstration, a vague shadow of disquiet passes over us, only to have been forgotten by the time the plane actually takes off.

Eventually space transportation will be regarded in the same way. But until then, we are a species that relies on , even if we have not yet fully conquered it.


Explore further

NASA image: Antares rocket at sunrise

This story is published courtesy of The Conversation (under Creative Commons-Attribution/No derivatives).
The Conversation

Citation: An unmanned rocket exploded. So what? (2014, October 30) retrieved 24 August 2019 from https://phys.org/news/2014-10-unmanned-rocket.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Oct 30, 2014
Meanwhile SpaceX is about to land their first stage on a platform out at sea! Even if this Orbital Science mission was a success the first stage would have still been lost, by design.

Oct 30, 2014
Something that should be considered is a criticism leveled by Elon Musk over two years ago about the Antares rocket: they are using Russian engines manufactured almost fifty years ago and sitting around in a warehouse since then. Not only are the designs old, the actual physical equipment is old. If anything, this should demonstrate the need for us to go back to the design board for many things, as SpaceX has and as NASA is for SLS. There's no reason on something as expensive as a rocket that we should be relying on technology from the 1960s.

You made the aircraft analogy; do we put unused jet engines from the 1960s on our modern jets, or are we constantly upgrading and improving them to improve both efficiency and safety?

Oct 30, 2014
It was a pretty awesome explosion though...that has to be worth something!

Oct 30, 2014
Two Taurus failures in a row, and lost science, plus this one with the Antares system to add to the list. One more failure and you'd probably started reading about ...Obituary Science.


Oct 31, 2014
do we put unused jet engines from the 1960s on our modern jets, or are we constantly upgrading and improving them to improve both efficiency and safety?


As a counterpoint, BMW (or some other team) used to build Formula 1 engines out of old engine blocks taken out of scrapped passenger vehicles that had reached the end of their miles, left them outside to corrode in the rain and cold for a year, and then machined them into high performing engines that pushed out a thousand horsepowers.

The rationale was, that after all that time and punishment, if the block was going to crack due to some internal flaw, it would have already done so.

Same thing with the 50 year old rocket engines. The turbopumps, seals, electronics, valves, are of course rebuilt and re-fitted becuse you obviously can't use a 50 year old O-ring and expect it to work. So what really is old is just some metal tubing and the big engine bell that stood the test of time.

Oct 31, 2014
Ariane 5 has a 100% success rate from 2002 to now (and that's 66 launches).
The first (test) launch was unsuccessfull and the second launch was partially succesfull, another launch later on was partially successful (but the satellite got at the right place in orbit), later in 2002 a launch failed completely.
So only two launches failed in total one of which was a test launch, and this results in a 97.5% sucsess rate.

Another point is that XCOR is making advanced ultra reliable and restartable rocket engines which is a big leap in technology.
SpaceX is on a similar path with more high power engines.
So we have new technology and older systems like Ariane 5 that perform ultra reliable.

Also, aircraft plunge down almost every day so I think most people consider safety a lot (especially when a big accident happened). You must be very naive not to consider it.

Oct 31, 2014

...
The rationale was, that after all that time and punishment, if the block was going to crack due to some internal flaw, it would have already done so.
...


The rationale is flawed.

Oct 31, 2014
The Challenger was killed by religion and politics. Morton Thiokol was recommended against as the booster builder because it needed to make the segmented boosters with the fatal seals, while most of the other bidders did not. The technical folk were overruled by the head, a Mormon, who picked Mormon Thiokol to build the failing units. Then, for political reasons, they had it fly to its demise when they should have waited to warm up. We did it for Reagan's political trick of a teacher in orbit.

Oct 31, 2014
I find it interesting and ironic that the Atlas 5, which also uses these old Soviet engines, was just used to put up classified spy satellites.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more