Britain's ill-fated Beagle 2 Mars probe should never have been given the go-ahead by the European Space Agency (Esa), an official report claims.
The lander did not call home when it was due to land on Christmas Day 2003
A peer review committee of Esa experts originally backed the lander only on condition that it was fully funded from the outset - but this did not happen.
In the circumstances, Esa's Science Programme Committee should not have agreed to the mission, the report says.
Beagle should have landed on Mars in 2003 but vanished without trace.
The full report, from the joint Commission of Inquiry set up by British science minister Lord Sainsbury and Esa director general Jean-Jacques Dordain, was released on Thursday.
"The Commission's view is that the SPC should not have confirmed the selection of Beagle 2, given the failure of the project to comply with the recommendations of the [Peer Review Committee which originally examined the lander proposal]," it said.
The failure of the mission, which cost about £50m, was a huge blow both to Esa and Britain's space community.
It was also a personal tragedy for Open University planetary scientist Professor Colin Pillinger, who first proposed the project and worked tirelessly to make it a success.
But the inquiry report identified crucial mistakes which undermined the mission from the beginning.
The most damaging were the way Beagle 2 was treated as a "scientific instrument" and not as a spacecraft in its own right, and the lack of properly organised funding.
Both these shortcomings were highlighted in a list of recommendations released by the Commission of Inquiry in May last year.
At that stage Esa and the British government agreed that for reasons of commercial confidentiality the full report would not be published.
But following widespread criticism of the decision, notably from Professor Pillinger himself, the full details were released today.
Beagle 2 was carried to Mars on board the Esa orbiter Mars Express, which is still circling the planet.
The decision to treat it as merely another of Mars Express's instruments was a "fundamental error" that led to "many subsequent problems", said the report.
The job of handling such a mission was too big for the Open University team behind Beagle 2, it was claimed.
The report said: "Beagle 2 should have been recognised as a complex, innovative spacecraft requiring management by an organisation with relevant experience - this was likely to be beyond the capability of a university-led group."
When Beagle 2 was approved in November 1999, its estimated cost without scientific instruments was £24m.
The only finance in place was £6m from consortium partners and £5m from the UK government. Additional funding was expected to come from private sponsors.
"The lack of guaranteed funding for Beagle 2 during its early stages seriously hindered the orderly build-up of the project engineering team, with the consequence that the design and development activities were delayed, exacerbating an already critical schedule," said the report.
By September 2000, the estimated cost at completion had risen to £35.4m, and the following year it reached £42.5m, plunging the project into a "funding crisis".
The Commission criticised Esa and the British authorities for not managing expectations of the mission in a more realistic way.
"It should have been made clear to all stakeholders, including the public, that the risk of failure was significantly higher than had been anticipated," it said.
To this day, no clear technical reason for the loss of Beagle 2 has been identified.
At the publication of the inquiry's recommendations in May of last year, Professor David Southwood, Esa's director of science, list four possible scenarios:
Professor Pillinger and his Beagle team believe the first of these was the most likely reason for Beagle's failure.
- Beagle entered an atmosphere that was thinner than expected, causing the probe to approach the surface too fast;
- the probe's parachute or cushioning airbags failed to deploy or deployed at the wrong time;
- Beagle's backshell or heatshield tangled with the parachute preventing it from opening properly;
- Beagle became wrapped up in its airbags or parachute on the surface and could not open.
Data returned by the US rovers, which managed to get down safely on to the surface of the Red Planet, suggested the engineering model of the atmosphere used by Beagle to plan its entry was out of step with the real conditions it would have experienced.