Australia have won the last eight Ashes series, a run stretching back 16 years, with England's last triumph in Test cricket's oldest contest coming under the captaincy of Mike Gatting on their 1986-87 tour.
England, however, have been making progress during the past 12 months, winning four straight Test series as well as setting a new national record of eight successive wins.
But as Vaughan acknowledged, wins over West Indies (twice), New Zealand and South Africa would be forgotten if England suffered another thumping along the lines of the last Ashes clash, in Australia in 2002-03, where the hosts had the series wrapped up in under 11 days' playing time.
"You can play against a number of teams and win but the question you get asked the most is 'how are you going to do against Australia?' That question is going to be answered this summer," Vaughan said in London.
"It is a challenge I am really looking forward to because when you face the biggest challenges you have to relish it and I am sure the team will be thinking the same way.
"We realise we are up against the best team in the world at this moment in time and probably the best team that has ever played.
"But we won't change our approach, we are going to play positive, attack and try to keep them under pressure for the whole of the summer.
"We have had 18 months of success and once you have had success you believe you can get some more; we will need all that belief.
"When you play Australia there are a lot of mind games, a lot of stuff written but you have to believe in yourself and retain your mental strength.
"If you get excited about playing against the best team in the world you have a chance of going out and performing."